Inorganic matrix-fabric system and method

ABSTRACT

A method of reinforcing a structural support, includes applying a reinforcement system comprising an AR-glass fibrous layer embedded in an inorganic matrix to the structural support. The AR-glass fibrous layer has a sizing applied thereon, and a resinous coating applied is applied over the sizing. The inorganic matrix is adherent to the resinous coating and the resinous coating is adherent to the sizing.

This application is a division of U.S. patent application Ser. No.10/209,471, filed Jul. 30, 2002, the entire disclosure of which isincorporated by reference herein.

FIELD OF THE INVENTION

This invention relates to structural supports, and more particularly toa method and reinforcement system for strengthening of such structuralsupports.

BACKGROUND OF THE INVENTION

Walls, columns and other structures constructed of materials such asconcrete or cement paste, brick or masonry units, and the like arewidely used as support structures. Tunnels, building structuralsupports, bridge supports, freeway overpass supports and parkingstructure supports are just a few of the many uses for thesecementitious structural supports. These supports may exist in a widevariety of shapes with circular, square and rectangular cross-sectionsbeing the most common. However, numerous other cross-sectional shapeshave been used, including regular polygonal shapes and irregularcross-sections. The size of structural supports also varies greatlydepending upon the intended use. Structural supports having heights andlengths exceeding 50 feet are commonly used in various applications.

It is common practice to reinforce concrete structural supports withsteel rods, mesh, or bars. The steel reinforcement provides a great dealof added structural strength (e.g., compression, tensile, flexuraland/or shear-resistance) to the support, but there have been numerousincidents of structural failure of these supports when subjected toasymmetric loads and horizontal displacement generated duringearthquakes or explosions. Concrete structures, while adequate incompression, are subject to cracking, collapse, and partial loss due tostresses associated with earthquakes, explosions, land subsidence andoverloading. Structural failure of such structures can have devastatingconsequences. Accordingly, there is a continuing need to enhance theability of reinforced and unreinforced concrete and cement structuralsupports to withstand the asymmetric loads and horizontal displacementswhich are applied during an earthquake or explosion.

One way of increasing the structural integrity of support structures isto include additional metal reinforcement prior to forming thestructural support. Other design features may be incorporated into thesupport structure fabrication in order to increase its resistance toasymmetric loading or horizontal displacement. However, there arehundreds of thousands of existing structural supports located inearthquake prone areas, which do not have adequate metal reinforcementor structural design to withstand high degrees of asymmetric loading orhorizontal displacement. Accordingly, there is a need to provide asimple, efficient and relatively inexpensive system for reinforcing suchexisting structural supports to prevent or reduce the likelihood offailure during an earthquake or explosion.

One approach to reinforcing cementitious structures, such as concretecolumns, is to wrap the exterior surface of the structure with acomposite reinforcement layer, or fabric reinforced plastic (FRP). InU.S. Pat. No. 5,607,527 to Isley, Jr., a composite reinforcement layerhaving at least one fabric layer located within a resin matrix iswrapped around the exterior surface of a concrete column. The fabriclayer has first and second parallel selvedges that extend around thecircumferential outer surface of the column in a direction substantiallyperpendicular to the column axis. Preferred fibers disclosed by Isleyinclude ones made from glass, polyaramid, graphite, silica, quartz,carbon, ceramic and polyethylene. Suitable resins suggested by thispatent include polyester, epoxy, polyamide, bismaleimide, vinylester,urethanes, and polyurea, with epoxy-based resins being preferred.

Another approach to reinforcing a cementitious structural support isdisclosed in U.S. Pat. No. 6,017,588 to Watanabe, et al. This patentdiscloses using an FRP to reinforce a structural support by forming aprimer layer on the surface of the support structure, forming, ifnecessary, a putty layer on the primer layer, applying an impregnatingresin on the primer layer (or putty layer) before, after or, before andafter, cladding with fiber sheets to allow the resin to penetrate intothe spaces in the fiber sheets, followed by curing the resin, theprimer, putty and impregnating resin. The primer, putty and impregnatingresin of this reference all include a resin composition. The disclosedfiber sheets may include carbon, aramid or glass fibers. The assertedadvantage of the reinforcement structure of this patent is increasedadherence of the reinforcement to the surface of the structural support.

Reinforcing FRP systems such as those described above can often beflammable, toxic and difficult to handle during application. They alsoprovide, after curing, poor fire resistance, poor bonding to theconcrete or brick being reinforced, and poor water/air permeability,resulting in the creation of moisture accumulation. Additionally, theyare fairly expensive and tend to delaminate upon failure.

A repair or reinforcement system for existing support structures or fornew construction support structures is needed.

SUMMARY OF THE INVENTION

In accordance with a first preferred embodiment of the presentinvention, a method for reinforcing a structural support is provided.This method comprises applying a reinforcement system having analkali-resistant fibrous layer embedded in an inorganic matrix to astructural support.

The preferred alkali-resistant fibrous layer is comprised of AR-glasshaving a sizing applied thereon, and a resinous coating applied over thesizing, the inorganic matrix being adherent to the resinous coating andthe resinous coating being adherent to the sizing. Unlike other types ofglass fibers, such as E-glass, AR-glass has a high degree of resistanceto alkali attack and higher strength retention over time. This is due tothe presence of an optimum level of Zirconia (ZrO₂) in the glass fibers.This type of glass exhibits a high degree of chemical resistance,resisting the very high alkalinity produced by the hydration ofconventional cementitious materials such as ordinary Portland cement.

The preferred inorganic matrix is comprised of cementitious materialsuch as cement, concrete or mortar. More preferably the inorganic matrixcomprises ordinary Portland cement having chopped reinforcing fibersdispersed throughout the cement. Such fibers may include those made fromcarbon, AR-glass, cellulose, rayon or polymeric materials, such asaramids, polyolefins, polyester, or hybrids thereof, for example.

According to another embodiment of the present invention, a method ofreinforcing a structural support comprises a) applying a first layer ofan inorganic matrix to the structural support, b) embedding a firstAR-glass open fibrous layer into the matrix, said AR-glass fibrous layerhaving a sizing applied thereon, and a resinous coating applied over thesizing, the inorganic matrix being adherent to the resinous coating, andthe resinous coating being adherent to the sizing, and c) applying asecond layer of the inorganic matrix to the first AR-glass open fibrouslayer. Additional fibrous layers and layers of inorganic matrix may alsobe added.

According to another embodiment of the present invention, a structuralsupport system is provided including a structural support, and areinforcement system adhered to the structural support, thereinforcement system comprising an AR-glass fibrous layer embedded in aninorganic matrix, wherein the AR-glass fibrous layer has a sizingapplied thereon, and a resinous coating applied over the sizing, theinorganic matrix being adherent to the resinous coating, and theresinous coating being adherent to the sizing.

According to a further embodiment of the present invention, a method ofreinforcing a structural support is provided comprising applying areinforcement system having a fibrous layer embedded in an inorganicmatrix to the structural support. The fibrous layer comprises PVAfibers, carbon fibers, aramid fibers, or a combination thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective cross-sectional view of a support structurehaving an exemplary reinforcement system according to the presentinvention.

FIG. 2 is a partial cross-sectional view of a support structure havingone embodiment of the reinforcement system of the present invention.

FIG. 3 is a front view of a concrete masonry unit (CMU) wall sample usedin testing alternative embodiments of the reinforcement system of thepresent invention.

FIG. 4 is a front view of a wall sample mounted in a test frame.

FIG. 5 is a diagram of a wall sample and test frame showing locations ofdisplacement measurements and directions of horizontal and verticalforces.

FIG. 6 is a front view of wall sample 1 showing crack growth duringin-plane shear testing.

FIG. 7 is a graph showing a backbone curve of load versus displacementfor the wall sample 1 and the backbone curve for the control sample.

FIG. 8 is a front view of wall sample 2 showing crack growth duringin-plane shear testing.

FIG. 9 is a graph showing a backbone curve of load versus displacementfor the wall sample 2 and the backbone curve for the control sample.

FIG. 10 is a front view of wall sample 3 showing crack growth duringin-plane shear testing.

FIG. 11 is a graph showing a backbone curve of load versus displacementfor the wall sample 3 and the backbone curve for the control sample.

FIG. 12 is a perspective view of a triplet sample having an exemplaryreinforcement system according to the present invention.

FIG. 13 is a graph showing a plot of load versus crosshead displacementfor the triplet tests.

FIG. 14 illustrates different configurations of fiber-reinforced-polymer(FRP) reinforcement systems applied to wall samples tested underconditions similar to those employed in testing Walls 1-3.

FIG. 15 is a graph comparing the engineering load increases for wallsamples 1-3 to wall samples having FRP reinforcement systems applied inthe different configurations shown in FIG. 14, versus the control samplehaving no reinforcement.

FIG. 16 is a graph comparing the wall displacements for wall samples 1-3with each other and also to previously tested FRP reinforced wallsamples.

DETAILED DESCRIPTION

A reinforcement system and a method of reinforcing a structural supportusing the reinforcement system of the present invention are provided.The reinforcement system has improved bonding with a cementitioussupport structure and is less likely to delaminate from the structuralsupport than existing reinforcement systems.

In accordance with the present invention, the following terms aredefined:

Adhesive bonded crossed laid fibers/mesh. Woven fabrics consisting oflayers of parallel textile yarns superimposed on each other at acute orright angles. These layers are bonded at the intersections of the yarnsby an adhesive, glue or by thermal bonding.

Cementitious material/composite. An inorganic hydraulically settingmaterial, such as those containing portland cement, mortar, plaster, flyash, slag, silica fume, metakaolin, gypsum, geopolymer and/or otheringredients, such as aggregate, including sand or gravel, additives oradmixtures, such as foaming agents, resins, including acrylicfortifiers, moisture resistant additives, shrinkage reducing admixtures(SRA), air-entraining (AE) admixtures, fire retardants, and choppedfibers, including glass, PVA, polypropylene, cellulose, graphite, orhybrids thereof.

Coatings/binders/finishes. Compounds, generally organic, applied tofabrics after processing (e.g., weaving or knitting) to protect thefibers and give the fabric stability.

Fiber. A general term used to refer to filamentary materials. Often,fiber is used synonymously with filament. It is generally accepted thata filament routinely has a finite length that is at least 100 times itsdiameter. In most cases, it is prepared by drawing from a molten bath,spinning, or by deposition on a substrate.

Filament. The smallest unit of a fibrous material. The basic unitsformed during drawing and spinning, which are gathered into strands offiber for use in composites. Filaments usually are of extreme length andvery small diameter. Some textile filaments can function as a yarn whenthey are of sufficient strength and flexibility.

Glass fiber. A fiber spun from an inorganic product of fusion that hascooled to a rigid condition without crystallizing.

Glass Filament. A form of glass that has been drawn to a small diameterand long lengths.

Inorganic Matrix. A matrix material comprising mostly inorganicingredients, such as ceramics, glasses, cementitious materials, andgeopolymers (inorganic resins), for example.

Knitted fabrics. Fabrics produced by interlooping chains of filaments,roving or yarn.

Mat. A fibrous material consisting of randomly oriented choppedfilaments, short fibers, or swirled filaments loosely held together witha binder.

Roving. A number of continuous filaments, strands, or collected into aparallel bundle.

Sizing. Compounds, generally organic, applied as a fine coating torovings after drawing of glass filaments in order to bind the individualfilaments together and stiffen them to provide abrasion resistanceduring processing (e.g., weaving or knitting).

Tensile strength. The maximum load or force per unit cross-sectionalarea, within the gage length, of the specimen. The pulling stressrequired to break a given specimen.

Tex. A unit for expressing linear density (or gauge) equal to the weightin grams of 1 kilometer of yarn, filament, fiber or other textilestrand.

Warp. The yarn, fiber or roving running lengthwise in a woven fabric. Agroup of yarns, fibers or roving in long lengths and approximatelyparallel.

Warp knit. Warp knitting is a type of knitting in which the yarnsgenerally run lengthwise in the fabric.

Weave. The particular manner in which a fabric is formed by interlacingyarns, fibers or roving. Weave can be further defined by “type ofweave”, such as leno weave, for example.

Weft. The transverse threads or fibers in a woven fabric. Those fibersrunning perpendicular to the warp. Also called fill, filling yarn orwoof.

Woven fabric. A material (usually a planar structure) constructed byinterlacing yarns, fibers, roving or filaments, to form such fabricpatterns as plain, harness satin, or leno weaves.

Yarn. An assemblage of filaments, fibers, or strands, either natural ormanufactured, to form a continuous length that is suitable for use inknitting, weaving or interweaving into textile materials. The assemblageof filaments, fibers or strands may have some or no twist.

Referring to FIG. 1, a reinforcement system 10 is shown reinforcing asupport structure 20. The present invention may be used to reinforce awide variety of support structures. Such support structures may include,for example, walls, beams, exterior insulation fabric systems (“EIFS”)slabs, chimneys, stacks, tanks, columns, silos, shafts, pipes, conduits,tunnels and the like. The support structure may be planar, circular, orany other shape. The invention is especially well suited for reinforcingsupport structures comprised of cementitious or masonry materials suchas cement, concrete, brick, and cinder block, which may be reinforced orunreinforced. One structural support especially suited for thereinforcement system of the present invention is unreinforced masonry(URM) walls.

The reinforcement system 10 comprises at least one alkali-resistant openfibrous layer 12 (two fibrous layers are shown in FIG. 1) and aninorganic matrix 14. The fibrous layers 12 are embedded within thematrix 14. The system 10 is applied to a surface of the supportstructure 20.

The following detailed description and examples describe use of thepresent invention to support a structure through application to onesurface of the structure; however, it will be understood by thoseskilled in the art that the present invention is not limited thereto,but may be applied to any number of surfaces depending on the shape ortype of support structure. Thus, for example, the reinforcement systemof the present invention may be applied to an outside surface and aninside surface of a wall of a building, pipe, wall or other structure.

The inorganic matrix 14 preferably comprises a cementitious material,such as cement paste, mortar or concrete, and/or other types ofmaterials such as gypsum and geopolymers (inorganic resins). Morepreferably the inorganic matrix comprises Portland cement having choppedfibers dispersed throughout the cement. Preferably the fibers areAR-glass fibers but may also include, for example, other types of glassfibers, aramids, polyolefins, carbon, graphite, polyester, PVA,polypropylene, natural fibers, cellulosic fibers, rayon, and hybridsthereof. The inorganic matrix may include other ingredients or additivessuch as fly ash, latex, slag and metakaolin, resins, such as acrylics,polyvinyl acetate, or the like, ceramics, including silicon oxide,titanium oxide, and silicon nitrite, setting accelerators, water and/orfire resistant additives, such as silioxane, borax, fillers, settingretardants, dispersing agents, dyes and colorants, light stabilizers andheat stabilizers, shrinkage reducing admixtures, air entraining agents,or combinations thereof, for example. In a preferred embodiment, theinorganic matrix includes a resin that may form an adhesive bond with aresinous coating applied to the alkali-resistant open fibrous layer.

Preferably the inorganic matrix has good bonding with the supportstructure. Portland cement, for example, has excellent bonding toconcrete, bricks and concrete masonry units (CMUs). The inorganic matrixmay contain curing agents or other additives such as coloring agents,light stabilizers and heat stabilizers, for example.

One inner surface 16 of the inorganic matrix is preferably in directcontact with a surface 22 of the support structure. Due to the preferredcompatibility of the inorganic matrix 14 with the support structure 20,there is no requirement that any adhesive material be applied betweenthe two materials, however the addition of an adhesive between, oramong, the inorganic matrix and the support structure is not precluded.

The alkali-resistant fibrous layers 12 are a reinforcement material forthe inorganic matrix 14. The fibrous layers 12 preferably provide longterm durability to the reinforcement system 10 in the highly alkalineenvironment of the inorganic matrix where the matrix is comprised ofmaterials such as cement paste, mortar, or concrete or geopolymers. Thefibrous layers may be comprised of glass fibers, PVA fibers, carbonfibers or aramid fibers, for example, or any combination thereof. Mostpreferably, the fibrous layers are comprised of AR-glass(alkali-resistant glass), such as that manufactured by Saint GobainVetrotex under the trademark Cem-FIL®. Unlike other types of glassfibers, such as E-glass, AR-glass has a high degree of resistance toalkali attack and a higher strength retention over time. This is due tothe presence of an optimum level of Zirconia (ZrO₂), e.g. preferablyabout 10% to about 25% ZrO₂, in the glass fibers. This type of glassexhibits a high degree of chemical resistance, resisting the very highalkalinity produced by the hydration of cementitious materials such asordinary Portland cement. In addition, AR-glass has superiorstrengthening properties necessary for use in earthquake andexplosion-resistant applications. It has high tensile strength andmodulus and does not rust. Although less preferred, other glass fibersmay be employed, such as E-glass, ECR-glass, C-glass, S-glass andA-glass, which are not inherently alkali-resistant, when such fibers arecoated with an alkali-resistant material, such as polyvinyl chlorideresinous coating.

The preferred AR-glass fibers are preferably produced as rovings oryarns. The linear density of the AR-glass fibers preferably ranges fromabout 76 Tex where yarns are employed to 2,500 tex where rovings areemployed. Where carbon fibers are used, they are preferably provided astows, with the filament count preferably ranging from about 3,000 to24,000. Preferred properties of the AR-glass include a virgin filamenttensile strength of at least about 185,000 psi or higher, Young'smodulus of elasticity of about 10-12 million psi, strain at breakingpoint of at least about 1.5% or higher, water uptake at less than about0.1%, and softening temperature of about 860° C.

The fibrous layers 12 may be formed, for example, by various methods ofweaving, such as plain or leno weave, or by knitting or laying ofcontinuous fibers. The fibrous layers may also be laid scrim or beformed from discontinuous or continuous fibers randomly oriented in anon-woven mat. Referring to FIG. 2, in one preferred embodiment, thefibrous layers 12 a and 12 b are glass fiber bi-directional fibrouslayers having two rovings per inch of fibers in one direction (e.g., theweft or fill direction) and one roving per inch of fiber in a direction90 degrees from the other direction (e.g., the warp direction). (Inanother preferred embodiment, the glass fiber bidirectional fibrouslayers have one roving per inch in each direction.) Varying fiberorientation, concentration, and fiber type permits tailoring of strengthto a specific application. Using different methods of knitting, braidingor weaving of the fabric may also be employed to produce a strongerreinforcement. The openings 18 in the fibrous layer 12 (see FIG. 1)should be sufficient to allow interfacing between the layers 14 a-c ofthe inorganic matrix 14 disposed on each side of the fibrous layers 12 aand 12 b.

The fibrous layer also preferably includes a sizing. Preferred sizingsfor use with a fibrous layer comprised of AR-glass include aqueoussizings comprising one of the following blends: 1) an epoxy polymer,vinyl and amine coupling agents and a non-ionic surfactant; 2) an epoxypolymer, amine coupling agent and a non-ionic surfactant; 3) an epoxypolymer, metacrylic and epoxy coupling agents, and cationic andnon-ionic surfactants (paraffin lubricants); 4) anhydrous polymerizedacrylate amine (for example, the substance disclosed in PCT PatentApplication No. WO 99/31025, which is incorporated herein by reference),metacrylic and epoxy coupling agents and a non-ionic surfactant; and 5)anhydrous polymerized epoxy amine (for example, as disclosed in U.S.Pat. No. 5,961,684 to Moireau et al., which is incorporated herein byreference), vinyl and amine coupling agents, and a non-ionic surfactant,each of the above blends being produced by Cem FIL Reinforcements ofSaint Gobain Vetrotex Cem-FIL® S.L., a Saint Gobain Vertrotex company.Preferably, the non-ionic surfactant comprises an organo-silane. Thesesizings are compatible with the preferred coatings for the AR-glassfibrous layer as described below and the cementitious matrices, andimprove initial glass strength and ease of fabric forming. The sizingspreferably comprise not more than 2.5% by weight, and most preferablyless than 1.5% by weight of the fibrous layer.

The fibrous layers may also include an optional coating 24. Coatings arepreferred where the fibrous layer is comprised of glass; however,coatings are not necessary where the fibrous layer is comprised ofAR-glass, PVA, carbon or aramid fibers. The coating 24 providesmechanical and chemical protection to the glass fibrous layers 12. Thecoating is preferably an acrylate and/or vinyl chloride containing apolymer or polymers. Coating 24 is preferably acrylic or PVC plastisol,but may be poly vinyl alcohol (PVA), styrene-butadiene rubber (SBR),polyolefin, acrylic acid, unsaturated polyesters, vinyl ester, epoxies,polyacrylates, polyurethanes, polyolefins, phenolics, and the like.Examples of preferred coatings include an acrylic coating manufacturedby Saint-Gobain Technical Fabrics, a Saint-Gobain company, under thelabel number 534 and a PVC plastisol coating manufactured bySaint-Gobain Technical Fabrics under the label number V38. The use ofPVC plastisol as a coating further improves the alkali resistance of thefibrous layer in the inorganic matrix. The use of acrylic as a coatingpromotes adherence of the fibrous layer to inorganic matrix, especiallywhere the matrix includes acrylic.

The coating can further contain a water resistant additives, such as,paraffin, and combination of paraffin and ammonium salt, fluorochemicals designed to impart alcohol and water repellency, such asFC-824 from 3M Co., organohydrogenpolysiloxanes, silicone oil,wax-asphalt emulsions and poly(vinyl alcohol) with or without a minoramount of poly(vinyl acetate). In addition, the flame retardants, suchas bromated phosphorous complex, halogenated paraffin, colloidalantimony pentoxide, borax, unexpanded vermiculate, clay, colloidalsilica and colloidal aluminum can be added to the coating. Further,optional ingredients, such as pigments, preservatives, dispersants,catalysts, fillers and the like may be added to the coating.

The coating is preferably applied by dip-coating the fibrous layer intothe coating, but may applied by any other technique known in the art,such as spraying, roll coating, and the like. The wt % of the coatingwill depend on the type of coating, preferably ranging from 10 to 200 wt% of the total weight of the coating and fiber. The coating can beapplied in various thicknesses. Preferably the coating is applied sothat no fibers of the fibrous layer protrude from the coating, however,the coating may alternatively be intermittently applied. Afterapplication of the coating 24, the openings 18 in the fibrous layers 12a and 12 b should be sufficient to allow interfacing between the layers14 a-c of the inorganic matrix 14 disposed on each side of the fibrouslayers.

According to a preferred embodiment of the present invention, the sizingand coating of an AR-glass fibrous layer are combined to optimizetensile performance and retention of tensile strength after aging, andto improve compatibility between the AR-glass, sizing, coating andcementitious matrix. Preferably the coating 24 is adherent to the sizingand the inorganic matrix 14 is adherent to the coating 24. A preferredcombination includes a sizing selected from the group consisting of 1)an epoxy polymer, vinyl and amine coupling agents and a non-ionicsurfactant; 2) an epoxy polymer, amine coupling agent and a non-ionicsurfactant; 3) an epoxy polymer, metacrylic and epoxy coupling agents,and cationic and non-ionic surfactants (paraffin lubricants); 4)anhydrous polymerized acrylate amine, metacrylic and epoxy couplingagents and a non-ionic surfactant; and 5) anhydrous polymerized epoxyamine, vinyl and amine coupling agents, and a non-ionic surfactant, anda polymeric coating selected from the group consisting of acrylic andPVC plastisol. Table 1 shows the results of tensile strength and tensileretention testing following a 5% NaOH accelerated aging test, aTri-alkali test (TAT) and a strand in cement (SIC) test using variouscoating/sizing combinations, as compared with uncoated AR-glass andE-glass. TABLE 1 TENSILE PROPERTIES OF COATED AND UNCOATED GLASS FIBERSTensile Strength (g/tex) Tensile Retention (%) Aged Aged Aged RetentionRetention Retention Sizing Coating Unaged TAT NaOH SIC TAT NaOH SICMaterial type Label Type Label Type Initial TAT NaOH SIC TAT NaOH SICCem-FIL 5197 5197¹ aqueous none none 40.65 greige resin Cem-FIL 5197 V385197 aqueous V38² PVC 60.14 61.24 57.05 101.83 94.86 resin plastisolCem-FIL 5197 534 5197 aqueous 534³ acrylic 62.40 39.89 37.97 63.93 60.85resin Cem-FIL 019/2 V38 019/2⁴ aqueous V38 PVC 71.97 74.15 64.90 103.0390.18 resin plastisol Cem-FIL 019/3 A15 019/3⁵ aqueous A15⁶ PVA 57.7539.58 68.54 resin Cem-FIL 020/2 K29 020/2⁷ anhydrous K29⁸ acrylic 88.289.93 45.04 31.5 101.96 51.07 35.71 resin Cem-FIL 020/2 P3 020/2anhydrous P3⁹ EEA/SA 86.69 88.85 53.1 32.7 102.49 61.25 37.72 resinCem-FIL 020/2 V38 020/2 anhydrous V38 PVC 84.28 89.17 63.47 54.2 105.8075.31 64.31 resin plastisol Cem-FIL 5197 K29 5197 aqueous K29 acrylic64.64 83.85 0 26 129.72 0.00 40.22 resin Cem-FIL 5197 P3 5197 aqueous P3EEA/SA 66.06 73.09 0 26.4 110.64 0.00 39.96 resin Cem-FIL 020/1 A15020/1¹⁰ anhydrous A15 PVA 73.93 47.61 64.40 resin E-glass K29 aqueousK29 acrylic 83.97 56 33.16 14.1 66.69 39.49 16.79 resin E-glass P3aqueous P3 EEA/SA 89.09 68.04 0 14.4 76.37 0.00 16.16 resin¹A blend of an epoxy polymer, vinyl and amine coupling agents and anon-ionic surfactant produced by Cem FIL Reinforcements.²Produced by Cem FIL Reinforcements.³Produced by Cem FIL Reinforcements.⁴A blend of an epoxy polymer, vinyl and amine coupling agents and anon-ionic surfactant produced by Cem FIL Reinforcements.⁵A blend of an epoxy polymer, metacrylic and epoxy coupling agents andnon-ionic and cationic surfactants produced by Cem FIL Reinforcements.⁶Produced by Cem FIL Reinforcements.⁷A blend of anhydrous polymerized epoxy amine, vinyl and amine couplingagents and a non-ionic surfactant produced by Cem FIL Reinforcements.⁸Produced by Cem FIL Reinforcements.⁹Produced by Cem FIL Reinforcements.¹⁰A blend of anhydrous polymerized acrylate amine, metacrylic and epoxycoupling agents and a non-ionic surfactant produced by Cem FILReinforcements.

In performing the 5% NaOH accelerated aging test, glass fiber specimenswere collected from good quality, undamaged fabric. Specimens from boththe machine and cross-machine direction were tested, each specimenhaving a length of 330 mm and a width of 50 mm. The specimens werefreely submerged in an alkali bath of 5% NaOH (sodium hydroxide) indistilled water for 28 days, with the bath being replaced after eachtest. Following conditioning in the alkali bath, the specimens werewashed with at least 1 liter of distilled water at least ten times.Following the washing, the fabric specimens were dried for seven days atroom temperature. Following drying, the fabric specimens were tested intension at a rate of 2 in/min using a 5 in. jaw span.

The TAT test was performed in accordance with the draft EuropeanStandard (Copyright 1997, CEN Members) prepared by the TechnicalCommittee for the European Committee for Standardization (CEN) andsubmitted to CEN members. Coated single end samples were placed in atri-alkali solution consisting of 1 g of NaOH, 0.5 g of Ca(OH)₂, and 4 gof KOH in 1 liter of distilled water at 60° C. After twenty-four hours,they were taken out and rinsed in tap water until a pH of 9 was reached.The samples were then placed in an acid solution of 0.5% HCL for onehour, taken out and rinsed in tap water until a pH of 7 was reached. Thesamples were then dried for one hour in a 60° C. oven. Following dryingin the oven, the samples were allowed to dry at room temperature fortwenty-four hours and then tested in tension.

SIC tests evaluate the alkali-resistance of glass strand or filaments incement, by measuring the tensile strength of a strand set in a block ofcement mortar. Well-stretched strands are installed in a metallic moldframe with the free ends coated with a coating mixture to protect theparts of the fibers that will not be in contact with the cement. Aftermixing the cement paste, having a water-to-cement ratio of 1:0.43 and acement-to-sand ratio of 1:0.34, the mold is filled with the cement pasteand vibrated to avoid formation of air bubbles near the strands. Thecement is allowed to set for one hour at room temperature, then fortwenty-three hours in cold water, after which the mold frame is removed.

The samples containing the cement block and strands are subsequentlyaged by soaking in water at 80° C. for four days. The samples are thenimmersed in cold water. The samples are then tested for tensile strengthusing a dynamometer.

The results of the TAT, NaOH accelerated aging, and SIC tests revealthat certain coated AR-glass fibers have improved tensile performanceover uncoated AR-glass and E-glass. The test results also indicate thatthe combination of sizing and coating affects the tensile performance.Anhydrous sizings outperform aqueous sizings. Further, the resultsreveal that a sizing/coating combination of Cem-FIL anhydrous sizing 020with the Cem-FIL PVC plastisol V38 coating provides the best tensileperformance.

The reinforcement system 10 can be applied to an existing structuralsupport 20 in the following exemplary manner. An outside surface 22 ofthe structural support 20 is wetted, preferably with water. (Prior towetting the outside surface of the structural support, it is preferredthat the surface be cleared of extraneous matter and cleaned with a mildsoap, if necessary.) A first layer 14 c of inorganic matrix is thenapplied by trowelling or similar coating technique to the wetted surface22 of the structural support 20. It should be understood that the matrixis in a wet or uncured state when it is applied to the support 20.Preferably, the thickness of the matrix layers ranges from {fraction(1/16)} to ¼ inch, and more preferably the thickness is approximately{fraction (1/8)} inch. If the thickness is too large, the matrix mayexhibit shrinkage cracking.

Once the first layer 14 c of inorganic matrix has been applied, analkali-resistant fibrous layer 12 b is embedded into the first layer 14c of the matrix. This may be performed by hand or by any automatedmethod. Generally, the fibrous layers will be provided in roll form andwill be cut from the roll to the desired shape and length. The fibrouslayers may be oriented in a variety of ways both with respect to theorientation of the support structure and with respect to the orientationof the other fibrous layers employed in the reinforcement system.Varying the orientation of the fibrous layers in these ways can improvethe strengthening and ductility characteristics of the reinforcementsystem.

After embedding a fibrous layer 12 b into the first layer 14 c ofmatrix, a second layer 14 b of inorganic matrix is applied over thefibrous layer 12 b. Again, this layer preferably has a thickness between{fraction (1/16)} and ¼ inch, and more preferably is approximately{fraction (1/8)} inch. After each layer 14 a-c of inorganic matrix isapplied, the matrix may be trowelled to provide a substantially smoothsurface.

As shown in the exemplary embodiment in FIGS. 1 and 2, after the secondlayer 14 b of inorganic matrix has been applied, a second fibrous layer12 a may be embedded in the second layer 14 b of matrix and a thirdlayer 14 a of inorganic matrix applied on top of the second fibrouslayer 12 a. If desired, a third fibrous layer may be embedded in thethird matrix layer 14 a and a fourth layer of inorganic matrix appliedon top of the third fibrous layer. Although it is preferred that thereinforcement system include between 1 and 3 fibrous layers and betweentwo and four inorganic matrix layers, additional fibrous layers andinorganic layers may be employed. The additional fibrous layers andlayers of inorganic matrix will be applied in the same manner asdescribed above. Once all the desired layers of the system have beenapplied, the system may be allowed to dry or cure on its own or may becured or set by any known means.

It is preferred that the reinforcement system 10 be applied to thesurface 22 of the support structure 20 so that substantially the entiresurface is covered. However, in certain applications, it may bebeneficial to apply the reinforcement system only to those portions ofthe support structure which are most likely to fail, or experience thehighest load in shear or bending, for example.

The reinforcement system increases the overall performance of thestructural supports by increasing the load to failure and by increasingthe deflection limits or ductility of the structural support system.Unlike the conventional fiber-reinforced polymer systems which may betoxic, difficult to handle, costly, subject to delamination, and havepoor fire resistance and water/air permeability, the reinforcementsystem of the present invention is easy to install, and has improvedfire resistance and improved bonding to concrete, concrete masonry units(CMU) and brick. Additionally the reinforcement system is less likely todelaminate from the structural support, allows the concrete or CMUs tobreathe due to similar air and water permeability, has a pleasantaesthetic appearance (can be blended into the concrete finish) and islower in cost.

SPECIFIC EXAMPLES

This invention and its advantages are further described with referenceto the following specific examples. The examples are merely intended tobe illustrative and not to be construed as limiting the scope of theinvention. In the following examples the method as described above wasemployed and tested on masonry wall and triplet samples. Results wereobtained which indicate significantly improved seismic strengthening forthe overall support system.

Example 1

Referring to FIG. 3, a lightly reinforced sample CMU block wall 100(wall 1) was constructed from standard 8×8×16 in. CMUs 110. The CMUswere constructed of a type N mortar, consisting of 1 part sand, 3 partsType I Portland cement, 1 part hydrated lime, and water in sufficientquantity to make the mortar mix workable by the technician. The wall wasten courses high with the top two and bottom two courses 16 in. widerthan the central six courses forming an “I” shape. All of the blocks inthe top two and bottom two courses were fully grouted to get better loadtransfer from a load frame (see FIG. 4) during testing and increase theprobability of wall failure not occurring within the wide top and bottomsections of the wall. A #4 steel reinforcing bar 120 was placed in thecells surrounding the central pier. All blocks containing steelreinforcing bars were fully grouted. Three-eighth inch face shell mortarbedding was used on the CMU blocks with the cross webs of units adjacentto grouted blocks fully bedded to prevent grout from flowing intoadjacent cells. Dur-o-wal joint reinforcement 130 was placed in the bedjoints between the top two and bottom two courses.

The reinforcement system of the present invention in this example wascomprised of an alkali-resistant glass fibrous layer comprising AR-glassmanufactured by Saint Gobain Corp. of St. Catherines, Ontario, Canada,under the trademark Cem-FIL®having a sizing comprised of a blend ofepoxy polymers, vinyl and amine coupling agents, and non-ionicsurfactants produced by Cem FIL Reinforcements under the product labelnumber 5197, and a coating comprised of an acrylic, and a cementitiousinorganic matrix manufactured by Quickrete Companies of Atlanta, Ga.under the trademark QuickWall®. The QuickWall® matrix was mixed in anelectric mortar mixer with water and an acrylic fortifier.

The AR-glass fibrous layer was a coated bi-directional fibrous layercomprising a warp knit weft inserted opened meshed grid, with tworovings per inch in the weft direction and one roving per inch in thewarp direction (see FIG. 2), and having polyester stitch yarns. Thecoating was comprised of an acrylic applied to the fibrous layer in a wt% of approximately 25-28% DPU. The rovings were approximately 1200 Tex.The AR-glass fibrous layer was cut from a 30-inch wide roll to thecorresponding dimensions of the sample CMU block wall 100.

A first layer of QuickWall® matrix was trowelled onto the sample wall atapproximately {fraction (1/8)} inch thick. A first AR-glass fibrouslayer was then pressed by hand into the wet matrix. The first AR-glassfibrous layer was oriented so that the weft direction of the fibrouslayer having two rovings was aligned horizontal to the bottom of thesample wall. Next a second layer of matrix approximately {fraction(1/8)} inch in thickness was applied by trowelling. A second AR-glassfibrous layer was then embedded by hand into the second layer of matrix.The second AR-glass fibrous layer was oriented so that the weftdirection of the fibrous layer was aligned perpendicular to the bottomof the sample wall. Finally, a third layer of matrix approximately{fraction (1/8)} inch in thickness was applied by trowelling onto thesecond fibrous layer to form a relatively smooth surface.

Before conducting the testing described below, the wall samplereinforced with the reinforcement system was allowed to cure for 30days.

The sample wall reinforced with the exemplary reinforcement system ofthe present invention according to the exemplary method of the presentinvention was tested for in-plane shearing at the U.S. Army EngineerResearch and Development Center, Construction Engineering ResearchLaboratory. Referring to FIGS. 3-5, the wall sample 100 with thereinforcement system 150 applied to it was set in a load test frame 160and clamped in place using bolted steel tubing 162 over the upper andlower specimen ears 102 and steel channels and rods 164 attached to theload frame 160 using eye bolts 166. The load floor test frame 160 wascomprised of a post-tensioned reinforced concrete reaction strong walland a steel frame. A 110-kip hydraulic actuator (not shown) with a ±20in. stroke was attached to the strong wall to provide horizontal forces(HF) to the sample wall 100 through a steel tube 170 bolted to the upperconcrete beam 168. Two 50-kip actuators (North and South) (not shown)with a ±3 in. stroke were attached to the steel frame and the horizontalsteel tube 170 to provide axial (vertical) load (FVS and FVN) tosimulate dead load above the wall specimen. The hydraulics for theactuator were computer-controlled.

The wall sample 100 was instrumented using two linear variabledifferential transducers and eight linear deflection (yo-yo) gages tomonitor wall sample movements (D1-D10) (See FIG. 5). For the in-planeshear testing, the South actuator was set in load control and the Northin stroke control; an initial 27 kip load was applied to each. The Northactuator (applying force FVN) that was under stroke control was alsoslaved to the stroke signal of the South vertical actuator (applyingforce FVS). Loading in this manner allowed the force in the verticalactuators to vary with respect to each other while maintaining aconstant 54 kip total axial load, thus forcing the top concrete beam ofthe test frame 160 to remain horizontal and parallel to the bottomconcrete beam of the test frame 160. This configuration put an in-planeshear load in the wall sample. Cyclic horizontal forces (HF) wereapplied to the wall sample using the horizontal actuator. Table 2 showsthe input time (sec) and displacement (in.) that the wall was subjectedto during the test. Displacement forces were terminated upon wall samplefailure. TABLE 2 Time Displacement (Sec) (in.) 0 0 12.5 0.02 25 0 37.5−0.02 50 0 62.5 0.02 75 0 87.5 −0.02 100 0 112.5 0.04 125 0 137.5 −0.04150 0 162.5 0.04 175 0 187.5 −0.04 200 0 212.5 0.06 225 0 237.5 −0.06250 0 262.5 0.06 275 0 287.5 −0.06 300 0 312.5 0.08 325 0 337.5 −0.08350 0 362.5 0.08 375 0 387.5 −0.08 400 0 412.5 0.1 425 0 437.5 −0.1 4500 462.5 0.1 475 0 487.5 −0.1 500 0 512.5 0.2 525 0 537.5 −0.2 550 0562.5 0.2 575 0 587.5 −0.2 600 0 612.5 0.3 625 0 637.5 −0.3 650 0 662.50.3 675 0 687.5 −0.3 700 0 712.5 0.4 725 0 737.5 −0.4 750 0 762.5 0.4775 0 787.5 −0.4 800 0 812.5 0.6 825 0 837.5 −0.6 850 0 862.5 0.6 875 0887.5 −0.6 900 0 912.5 0.8 925 0 937.5 −0.8 950 0 962.5 0.8 975 0 987.5−0.8 1000 0 1012.5 1 1025 0 1037.5 −1 1050 0 1062.5 1 1075 0 1087.5 −11100 0 1112.5 1.2 1125 0 1137.5 −1.2 1150 0 1162.5 1.2

Referring to FIG. 6, during the course of the wall test for wall 1,cracking of the reinforcement began during the 0.2 inch horizontaldisplacement cycles at the lower corners (LS and LN) of the sample andthen began to propagate downward as a typical concrete shear crack ataround 45 degrees. At 0.6 and 0.8 inch horizontal displacements,cracking began to appear intermittently in the middle of the centralpier starting the formation of an X-crack. At 1.0 inch displacement,significantly more cracks appeared diagonally from the upper northreentrant corner (UN) downward. At the same time cracking began growingupward and at a 45-degree angle from that corner. Finally, at 1.2 inchdisplacement, the reinforcement cracked from the upper north reentrantcorner (UN) diagonally across the entire sample to the south reentrantcorner (LS), and the back face of the pier CMU blocks sheared off andfell to the floor ending the test.

FIG. 7 shows a backbone curve of load versus displacement (at D4 and D7)for the wall 1 sample as well as the backbone curve for the controlsample. The control sample was a CMU wall as described above without theapplication of the reinforcement system.

Example 2

A second wall sample 200 (wall 2) having a reinforcement system appliedwas tested using the same testing method as described above with respectto wall sample 1. Wall 2 was made in accordance with the materials andprocedure described in Example 1 and the reinforcement system applied towall 2 was made with the materials described in Example 1. The onlydifference between Examples 1 and 2 is with respect to the method ofreinforcement application. In applying the reinforcement system of wall2, the first glass fibrous layer was oriented so that the weft directionof the fabric having two rovings was at a 45° angle to the bottom of thewall running from the top left corner (US) to the bottom right corner(LN). The second glass fibrous layer was oriented so that the weftdirection of the fibrous layer was aligned perpendicular to the bottomof the sample wall 200.

Referring to FIG. 8, the reinforcement of wall 2 began to show crackingat 0.3 inch horizontal displacement in the same way as wall 1. Cracksappeared at the lower reentrant corners (LS and LN) and propagateddownward, as is typical with concrete shear crack growth. At 0.6 inchhorizontal displacement, an X-crack began to appear across the centralpier section of the wall. Then at 0.8 inch displacement thereinforcement developed a horizontal crack near the second pier bedjoint. The back face of the CMU blocks sheared off and the wall began tobuckle ending the test.

FIG. 9 shows a backbone curve of load versus displacement (at D4 and D7)for the wall 2 sample as well as the backbone curve for the controlsample. Again, the control sample was a CMU wall without the applicationof the reinforcement system.

Example 3

A third wall sample 300 (wall 3) having a reinforcement system appliedwas tested using the same testing method as described above with respectto wall samples 1 and 2. Wall 3 was made in accordance with thematerials and procedure described in Example 1. The reinforcement systemapplied to wall 3 was made with the material compositions described inExample 1, except that the final layer of matrix applied to thereinforcement was comprised of QuickWall Sanded® material fromQuickCrete having more sand than the regular QuickWall® product.

The reinforcement system applied to wall 3 included a third glassfibrous layer embedded in the third layer of matrix and a fourth layerof matrix (the QuickWall Sanded® material) applied as the top coat. Inapplying the reinforcement system of wall 3, the first glass fibrouslayer was oriented so that the weft direction of the fabric having tworovings was at a 45° angle to the bottom of the wall running from thetop left corner (US) to the bottom right corner (LN). The second glassfibrous layer was oriented so that the weft direction of the fibrouslayer was at a 45° angle to the bottom of the wall running from the topright (UN) to the bottom left corner (LS). The third glass fibrous layerwas oriented so that the weft direction of the fibrous layer was alignedperpendicular to the bottom of wall 3.

Referring to FIG. 10, cracking in the reinforcement initiated at 0.2inch horizontal deflection in the lower north reentrant corner (LN).From 0.3 inch to 1.0 inch displacement, the crack grew along the bedjoint at that location to a length of 7 inches. At 0.4 inch horizontaldisplacement a crack began in the other lower reentrant corner (LS),angling downward. It continued on the next amplitude of horizontaldisplacement. At 0.8 inch displacement, a new crack started there andfollowed the bed joint approximately 8 inches. A diagonal crack alongthe same line as the wall 1 failure initiated at 0.5 inch horizontaldisplacement and grew during the 0.8 displacement cycles. At 0.8 inchdisplacement, a crack initiated in the upper north reentrant corner (UN)angling upward. Then at 1.0 inch horizontal displacement, several morecracks initiated at that corner and all grew upward at varying angles.During the 1.0 inch horizontal displacement cycles the CMU blocks beganto shear, and since the wall was in imminent danger of collapse, thetest was halted. Examination of the ends and rear of the wall revealedthat the back face had a well-developed X-crack and the front face wasbeginning to shear off just behind the reinforcement. The reinforcementdid not fail during this test.

FIG. 11 shows a backbone curve of load versus displacement (at D4 andD7) for the wall 3 sample as well as the backbone curve for the controlsample. Again, the control sample was a CMU wall without the applicationof the reinforcement system.

Example 4

Referring to FIG. 12, three triplet samples 400 were constructed usingstandard 8×8×16 inch CMUs. The triplet samples 400 were constructed fromthree blocks 402, 404 and 406, placed in a stack-bond with the centerblock 404 offset by ¾ inch. The reinforcement system 410 applied to thethree triplet samples was made with the material compositions describedin the above Examples, except that the matrix layers were comprised ofQuickWalle Sanded material as opposed to the regular QuickWall® product.

The application process of the reinforcement system for the threetriplet samples 400 was identical to the application process for thethree wall samples described above. The first triplet sample (triplet 1)received two glass fibrous layers. The first glass fibrous layer of thefirst triplet was oriented so that the weft direction of the fibrouslayer having two rovings was aligned horizontal to the bottom of thetriplet standing on end (as shown in FIG. 2). The second glass fibrouslayer was oriented so that the weft direction of the fibrous layer wasaligned perpendicular to the bottom of the triplet. The second tripletsample (triplet 2) also received two glass fibrous layers. The firstglass fibrous layer of the second sample was oriented so that the weftdirection of the fabric was at a 45° angle to the bottom of the tripletrunning from the top left corner to the bottom right corner. The secondglass fibrous layer was oriented so that the weft direction of thefibrous layer was aligned perpendicular to the bottom of the tripletsample. The third triplet sample (triplet 3) received three glassfibrous layers. The first glass fibrous layer of the third tripletsample was oriented so that the weft direction of the fabric was at a45° angle to the bottom of the triplet running from the top left cornerto the bottom right corner. The second glass fibrous layer was orientedso that the weft direction of the fibrous layer was at a 45° angle tothe bottom of the triplet running from the top right to the bottom leftcorner. The third glass fibrous layer was oriented so that the weftdirection of the fibrous layer was aligned perpendicular to the bottomof the triplet. As with the wall samples, the triplets were allowed tocure for thirty days before testing.

The triplets 400 were tested in a million-pound test frame. The sampleswere placed on the load platen of the test frame so that the center,offset block was up. Steel plates were bolted to the ends of the tripletsamples and tightened to apply a 4800-pound clamping force on thetriplets. This force corresponds to the 150-psi axial load applied tothe wall samples. The triplets were then loaded in compression at aconstant load rate of 0.0027 in./sec. Table 3 lists the maximum loadsfor each of the triplet samples. TABLE 3 MAXIMUM LOADS FOR TRIPLET TESTSTriplet ID Maximum Load (lb) 1 43,175 2 47,350 3 48,031

Since the reinforcement system was applied to only one face of thetriplet samples, there was less resistance to the load on the face withno reinforcement applied. This resulted in a shearing of the rear faceshell and compression of the center face on the back to a point levelwith the adjoining block faces. In all instances, the face with thereinforcement applied resisted the compression. FIG. 13 is a plot ofload versus crosshead displacement for the triplet test.

Triplet 1 had the least damage to the reinforcement system. There were afew hairline cracks approximately 1 inch long distributed along themortar joints at about a 30 degree angle from the horizontal.

Triplet 2 showed the most damaged to the reinforcement. Cracks developedat the reentrant corners on the triplet. A large one developed at thebottom and smaller ones developed at the top. Examination of thereinforcement revealed initiation of some delamination. After removingthe triplet from the test machine, the CMU face of the center block waspulled free of the reinforcement, which remained intact.

Triplet 3 yielded small hairline cracks at the top reentrant corners ofthe reinforcement, which was the only visible damage to thereinforcement side of the specimen.

Results

The benefit of applying the AR-glass fabric reinforced inorganic matrixto support structures such as the walls described above is to addstrength to the support structure and to improve structure performanceby increasing deflection limits. These benefits result in improvedearthquake and explosion resistance. The backbone curves, as shown inFIGS. 7, 9, and 11 indicate the engineering strength of the supportstructure under consideration. The engineering strength is defined asthe peak load transcribed by the back bone curve. For engineeringpurposes, the engineering strength is a better indicator of the systemperformance than the measured peak load because it incorporates a factorof safety that may or may not be present when considering the peak loadvalue.

For each reinforced wall sample tested, the engineering load improvedover a control sample having no reinforcement. Wall 1, exhibiting a 57%strength increase over the control, performed the best, followed by Wall3 having a 42% increase and Wall 2 having a 38% increase. FIG. 14illustrates different configurations of fiber-reinforced-polymer (FRP)reinforcement systems applied to wall samples tested in prior tests atthe U.S. Army Engineer Research and Development Center, ConstructionEngineering Research Laboratory under similar conditions. The FRPreinforced samples were loaded in in-plane shear with 54 kips axial loadapplied to them. FIG. 15 compares the engineering load increases forsample Walls 1-3 to sample walls having FRP reinforcement systemsapplied in the different configurations shown in FIG. 14, over thecontrol sample having no reinforcement.

The maximum horizontal load each wall resisted, along with theengineering load and their comparisons to the control walls are listedin Table 4. The order of maximum horizontal load resistance for eachwall is the same as the engineering load order. In addition to providingthe maximum strength increase, Wall 1 also exhibited the bestdisplacement prior to failure. FIG. 16 compares the wall displacementswith each other and also to FRP reinforced wall samples tested in priortests. Table 5 lists the maximum displacement between gages D7 and D4(See FIG. 5) for Walls 1-3, and compares those values to the with thecontrol having no reinforcement applied. The walls tested showedimprovements ranging from 29% for Wall 2 to 44% for Wall 1. TABLE 4 WALLLOAD COMPARISONS SHOWING MAXIMUM ENGINEERING LOAD Max Load (L) (EL)Δ_(L) Δ_(EL) Δ_(L) Δ_(EL) Wall No. (kips) (kips) (kips) (kips) (%) (%) 155.7 53.28 17.68 19.37 46.50 57.12 2 49.96 46.81 11.94 12.9 31.40 38.043 53.25 48.26 15.23 14.35 40.06 42.32 Control 38.02 33.91

TABLE 5 WALL DISPLACEMENT COMPARISONS SHOWING MAXIMUM DISPLACEMENT MaxDisplacement Δ_(S) Δ_(S) Wall No. (inches) (inches) (%) 1 1.224 0.87643.97 2 0.577 0.229 29.13 3 0.631 0.283 37.64 Control 0.348

To summarize the results of the testing of Wall Samples 1-3, theAR-glass reinforced inorganic matrix reinforcing system of the presentsystem added 47-53 kips of horizontal resistance, or 38%-57% to theengineering strength of the wall samples in in-plane shear. The materialadded 0.58-1.22 inches of horizontal displacement, or 29%-44% to thewall samples in in-plane shear. Wall 1, having two fibrous layers offabric applied at 0° and 90° to each other and the wall performed betterthan the other configurations. Three glass fibrous layers, two alignedat ±45° and the third at 0° and 90° to the wall sample, performed betterthan two glass fibrous layers aligned at 0° and 90° to each other but±45° to the wall sample. All wall failures were due to shear between thefront and rear faces of the blocks. There were no delaminations of thereinforcement system of Walls 1-3 from the CMU walls.

1. A method of reinforcing a structural support, comprising applying areinforcement system comprising an AR-glass fibrous layer embedded in aninorganic matrix to the structural support, wherein said AR glassfibrous layer has a sizing applied thereon, and a resinous coatingapplied over said sizing, said inorganic matrix being adherent to saidresinous coating, and said resinous coating being adherent to saidsizing.
 2. The method of claim 1, wherein the fibrous layer is abi-directional open fibrous layer having two rovings per inch in a weftdirection and one roving per inch in a warp direction
 3. The method ofclaim 1, wherein the fibrous layer is a bidirectional open fibrous layerhaving one roving in a weft direction and one roving in a warpdirection.
 4. The method of claim 1, wherein the fibrous layer iscomprised of AR-glass yarns.
 5. The method of claim 1, wherein thefibrous layer is formed by needling, weaving, knitting, or adhesivebonding of cross laid mesh.
 6. The method of claim 1, wherein thefibrous layer is formed from continuous or discontinuous fibers randomlyoriented in a non-woven mat.
 7. The method of claim 1, wherein theinorganic matrix comprises a cementitious material.
 8. The method ofclaim 7, wherein in the inorganic matrix includes a resin which forms anadhesive bond with said resinous coating.
 9. The method of claim 1,wherein the cementitious material includes chopped alkali-resistantglass fibers.
 10. The method of claim 1, wherein the coating comprisesat least one polymer containing one or more of an acrylate and a vinylchloride.
 11. The method of claim 1, wherein the coating comprises anacrylic.
 12. The method of claim 1, wherein the coating comprises PVCplastisol.
 13. The method of claim 1, wherein the structural support iscomprised of an unreinforced masonry.
 14. The method of claim 1, whereinthe structural support is comprised of concrete.
 15. The method of claim1, wherein the structural support is comprised of bricks.
 16. The methodof claim 1, wherein the inorganic matrix is applied in two or morelayers.
 17. The method of claim 1, wherein the coating comprises PVCplastisol and the sizing comprises a blend of anhydrous polymerizedepoxy amine, vinyl and amine coupling agents and a non-ionic surfactant18. A method of reinforcing a structural support, comprising: applying afirst layer of an inorganic matrix to the structural support; embeddinga first AR-glass open fibrous layer into the matrix, said AR-glassfibrous layer having a sizing applied thereon, and a resinous coatingapplied over said sizing, said inorganic matrix being adherent to saidresinous coating, and said resinous coating being adherent to saidsizing; and applying a second layer of the inorganic matrix to the firstAR-glass open fibrous layer.
 19. The method of claim 18, wherein thesteps of applying a first and second layer of the inorganic matrixincludes trowelling the matrix.
 20. The method of claim 18, wherein thefibrous layer is embedded into the matrix by hand.
 21. The method ofclaim 18, further comprising: embedding a second AR-glass fibrous layerinto the second layer of matrix; and applying a third layer of theinorganic matrix to the second AR-glass fibrous layer.
 22. The method ofclaim 18, further comprising: embedding a third AR-glass fibrous layerinto the third layer of the inorganic matrix, and applying a fourthlayer of the inorganic matrix to the third AR-glass fibrous layer. 23.The method of claim 21, wherein the first and second fibrous layer is abidirectional fibrous layer comprising two rovings of fibers per inch inthe weft direction and one roving of fibers per inch in the warpdirection.
 24. The method of claim 23, wherein one of the first orsecond fibrous layers is orientated so that the weft direction isparallel to the bottom of the support structure and the other of thefirst or second fibrous layers is orientated so that the weft directionis perpendicular to the bottom of the support structure.
 25. The methodof claim 23, wherein one of the first or second fibrous layers isoriented at a clockwise 45° angle to the bottom of the structuralsupport and the other of the first or second fibrous layers is orientedat a counterclockwise 45° to the bottom of the structural support. 26.The method of claim 22, wherein each of the first, second and thirdfibrous layer is a bidirectional fibrous layer comprising two rovings offibers in the weft direction and one roving of fibers in the warpdirection, and wherein one of the fibrous layers is oriented at aclockwise 45° angle to the bottom of the structural support, one of thefibrous layers is oriented at a counterclockwise 45° angle to the bottomof the structural support, and one of the fibrous layers is oriented sothat the weft direction of the fibrous layer is parallel to the bottomof the structural support.
 27. The method of claim 18, wherein thelayers of inorganic matrix are approximately {fraction (1/8)} inchthick.
 28. The method of claim 18, wherein the wetting step comprisesspraying the structural support with water.
 29. The method of claim 18,further comprising wetting the structural support, and wherein the stepof wetting the structural support is performed prior to applying thefirst layer of inorganic matrix.
 30. The method of claim 18, wherein thecoating comprises PVC plastisol and the sizing comprises a blend ofanhydrous polymerized epoxy amine, vinyl and amine coupling agents and anon-ionic surfactant.
 31. A method of reinforcing a structural support,comprising: applying a first layer of an inorganic matrix to thestructural support; embedding a first AR-glass open fibrous layer intothe matrix, said AR-glass fibrous layer having a resinous coatingapplied thereon, said inorganic matrix being adherent to said resinouscoating; applying a second layer of the inorganic matrix to the firstAR-glass open fibrous layer; embedding a second AR-glass fibrous layerinto the second layer of matrix; and applying a third layer of theinorganic matrix to the second AR-glass fibrous layer; wherein the firstand second fibrous layer is a bi-directional fibrous layer, and whereinone of the first or second fibrous layers is orientated so that the weftdirection is parallel to the bottom of the support structure and theother of the first or second fibrous layers is orientated so that theweft direction is perpendicular to the bottom of the support structure.32. A method of reinforcing a structural support, comprising applying areinforcement system comprising a fibrous layer embedded in an inorganicmatrix to the structural support, wherein said fibrous layer comprisesPVA fibers, carbon fibers, aramid fibers, or a combination thereof.